The present invention relates to a device for connecting the gangway bellows cover and the chassis of articulated vehicles, in particular for articulated vehicles such as buses.
In articulated or jointed vehicles, such as city buses, the connection between the two coaches of which the vehicle consists is made by means of rotary platforms able to allow both passenger transit and standing in the connecting zone.
The connection must, necessarily guarantee safety conditions even when the vehicle is cornering, that is to say, even when the two coaches are not aligned with each other.
There are prior art connecting devices consisting of a substantially inverted U-shaped gangway bellows cover whose ends are connected to the free ends of the two coaches, in such a way that the gangway bellows cover covers the rotary platform zone and deforms when the vehicle adopts configurations in which the two coaches are not aligned.
In particular, the gangway bellows cover-style connecting device has an accordion shape, that is to say, it has a plurality of U-shaped bands made of flexible material, usually plasticized fabric, which are joined together longitudinally.
There is also usually an additional inner gangway bellows cover, extending between a lateral wall of the gangway bellows cover and the rotary platform to provide improved protection for the joint between the lateral wall of the gangway bellows cover and the rotary platform.
The outer gangway bellows cover and the additional inner gangway bellows cover are therefore stably fixed to the corresponding ends of the two coaches of the vehicle by means of suitably made connecting systems. These connecting systems comprise a metal section having on one side an edge which can be connected gripper-style to one end of the gangway bellows cover, and on the other side an engagement portion which can be inserted in a corresponding groove in the vehicle chassis. The dimensions of the engagement portion are smaller than the corresponding groove in the vehicle chassis, allowing the insertion, between the engagement portion and the groove, of a rubber fixing seal which holds the section permanently in position and, therefore, renders integral with each other the gangway bellows cover and the chassis of the two coaches belonging to the vehicle.
However, connecting systems of the type described above have significant disadvantages.
First, with the passage of time the seal may lose its elastic properties and therefore allow movements of the section inside the groove in the chassis, and it may even cause detachment of the section with consequent uncoupling of the gangway bellows cover from the chassis.
Moreover, the end of the gangway bellows cover gripped by the gripper action of the above-mentioned edge of the section is subject to substantial deformations at said edge of the section, due to the movements to which the gangway bellows cover is subjected while the vehicle is moving (it should be noticed that the portion of the gangway bellows cover gripped by the section remains stationary whilst the adjacent portion of the gangway bellows cover bends considerably). This causes many breaks in the gangway bellows cover, even after it has been used for a short period of time, with the consequent need for repair or substitution of the gangway bellows cover.
Moreover, the prior art gangway bellows covers suffer from the problem of requiring removal of the seal and the engagement portion if the gangway bellows cover must be removed, for example for cleaning, maintenance or inspection of the vehicle rotary platform. This is very time consuming, involving highly complex operations and the risk of damaging the seal which may necessitate its substitution when the gangway bellows cover is subsequently refitted on the vehicle.